CVE-2026-128347: ExcelJS through 4.4.0 Arbitrary File Read via WorkbookWriter addImage Filename
Noroxi assessment
Priority: Monitor (action score 34/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
- According to the record, no fixed version is available yet.
Low priority for now. Update when a fix is released; follow the vendor's advisory.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
ExcelJS through 4.4.0 contains an arbitrary file read vulnerability in the streaming WorkbookWriter that allows attackers to read local files by supplying crafted image filenames to addImage. Attackers can inject ../ path segments into user-controlled image paths, causing addMedia to embed any file readable by the Node.js process under xl/media in the generated workbook.
- Published
- Nov 13, 2026
- Updated
- Nov 13, 2026
- EPSS
- —
- CWE
- CWE-73
Report tools
Action score
34
Low priority for now.
- CVSS
- 34 / 40 · 8.7 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · —
CNA vs NVD score
- NVD
- —
- CNA · VulnCheck
- 8.7
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- No fixed version yet
If any of these changes, we'll tell you in the daily email digest.
Is your version affected? Check itNoroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (VulnCheck). Independent of NVD's CPE analysis and usually ahead of it.
exceljs exceljs
- up to and including 4.4.0affected · semver
Same product
exceljs: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-78207exceljs through 4.4.0 Prototype Pollution via deepMerge Reached From Note Serialization37Monitor
- CVE-2026-128346ExcelJS through 4.4.0 Resource Exhaustion via Streaming WorkbookReader Temporary Files34Monitor
- CVE-2026-128344ExcelJS through 4.4.0 Memory Exhaustion via Oversized Image Anchor Column34Monitor
Published before and after this one in the same product
- ← EarlierCVE-2026-128343Nov 13, 2026 · ExcelJS through 4.4.0 Denial of Service via Oversized Row Number34Monitor
- ← EarlierCVE-2026-128345Nov 13, 2026 · ExcelJS through 4.4.0 ReDoS via slideFormula Shared Formula Translation27Monitor
- Later →CVE-2026-128348Nov 13, 2026 · ExcelJS through 4.4.0 Formula Injection via Table Totals Row Column Names9Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- Matéo Florian Callecfinder
Not on record for this CVE: EPSS history · patch commit or PR link · variant or chain candidate · public bounty program.
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-73 · External Control of File Name or PathCVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
- Leverage Alternate EncodingCAPEC-267likelihood: High · High
- Using Slashes and URL Encoding Combined to Bypass Validation LogicCAPEC-64likelihood: High · High
- URL EncodingCAPEC-72likelihood: High · High
- Manipulating Web Input to File System CallsCAPEC-76likelihood: High · Very High
- Using Escaped Slashes in Alternate EncodingCAPEC-78likelihood: High · High
- Using Slashes in Alternate EncodingCAPEC-79likelihood: High · High
- Using UTF-8 Encoding to Bypass Validation LogicCAPEC-80likelihood: High · High
Change log (1)
- Exploit maturity— → none
For records you follow, these changes also arrive as notifications. →
References
Show all references (4 more)Show less
- github.com/exceljs/exceljs/blob/v4.4.0/lib/stream/xlsx/workbook-writer.js#L124-L130
- github.com/exceljs/exceljs/blob/v4.4.0/lib/stream/xlsx/workbook-writer.js#L230-L237
- github.com/mateocallec/exceljs-hardened/security/advisories/GHSA-f9m8-8qmf-qq29
- www.vulncheck.com/advisories/exceljs-through-4.4.0-arbitrary-file-read-via-workbookwriter-addimage-filename
Vendor advisories and official records. Exploit/PoC links are deliberately left out.